Re: [RFC 02/14] efi_loader: library function efi_dp_merge

On 26.04.24 16:30, Ilias Apalodimas wrote:

Hi Heinrich,

On Fri, 26 Apr 2024 at 17:13, Heinrich Schuchardt heinrich.schuchardt@canonical.com wrote:

...

Provide a function to append a device_path to a list of device paths that is separated by final end nodes.

Signed-off-by: Heinrich Schuchardt heinrich.schuchardt@canonical.com

include/efi_loader.h | 3 +++ lib/efi_loader/efi_device_path.c | 31 +++++++++++++++++++++++++++++++ 2 files changed, 34 insertions(+)

diff --git a/include/efi_loader.h b/include/efi_loader.h index 9600941aa32..a7d7b8324f1 100644 --- a/include/efi_loader.h +++ b/include/efi_loader.h @@ -944,6 +944,9 @@ struct efi_load_option {

struct efi_device_path *efi_dp_from_lo(struct efi_load_option *lo, const efi_guid_t *guid); +struct efi_device_path *efi_dp_merge(const struct efi_device_path *dp1,

•                                efi_uintn_t *size,
  

•                                const struct efi_device_path *dp2);
  

  struct efi_device_path *efi_dp_concat(const struct efi_device_path *dp1, const struct efi_device_path *dp2, bool split_end_node);

diff --git a/lib/efi_loader/efi_device_path.c b/lib/efi_loader/efi_device_path.c index 46aa59b9e40..16cbe41d32f 100644 --- a/lib/efi_loader/efi_device_path.c +++ b/lib/efi_loader/efi_device_path.c @@ -270,6 +270,37 @@ struct efi_device_path *efi_dp_dup(const struct efi_device_path *dp) return ndp; }

+/**

• • efi_dp_merge() - Concatenate two device paths separated by final end node
• • @dp1: first device path
• • @size: pointer to length of @dp1, total size on return
• • @dp2: second device path
• • Return: concatenated device path or NULL
• */

+struct efi_device_path *efi_dp_merge(const struct efi_device_path *dp1,

•                                efi_uintn_t *size,
  

•                                const struct efi_device_path *dp2)
  

+{

•   efi_uintn_t len, len1, len2;
  

•   struct efi_device_path *dp;
  

•   u8 *p;
  

•   len1 = *size;
  

•   len2 = efi_dp_size(dp2) + sizeof(END);
  

•   len = len1 + len2;
  

•   dp = efi_alloc(len);
  

•   if (!dp)
  

•           return NULL;
  

•   memcpy(dp, dp1, len1);
  

•   p = (u8 *)dp + len1;
  

•   memcpy(p, dp2, len2);
  

•   *size = len;
  

Can't we just use efi_dp_concat()?

efi_dp_concat cannot be used to put a device-path end-node in between two device-paths that are concatenated. We need that separator in the load options.

Best regards

Heinrich

Thanks /Ilias

...

•   return dp;
  

+}

• /**
  • efi_dp_concat() - Concatenate two device paths and add and terminate them

  •               with an end node.
    

-- 2.43.0